hmm, try capping off the two ends to the BoV and plug the vac line. If that fixes it then it's your BoV. also try reaching in near the TB and pushing the throttle to idle and see if it changes.

how the fuck does a BOV effect runnning conditions ??? cancel that, im not in a mood too debate on stuff right now !

If it's leaking air dub. It's the same as any other vacuum leak. Aside from that if it's not vented back to intake then you'll run rich between shifts.

does it have the stock turbo inlet pipe? If so, pull it off and see if it's cracked right where it slips on the turbo.

That stock inlet pipe is a notorious piece of shit for leaks. However I think it's fixed, seeing as how old this topic is.

Gotcha.